A new programmable ultrasound machine and software interface is described. The software interface takes advantage of the open architecture of the new machine to provide real-time access to the digital image formation pipeline and control of the parameters of acquisition. The first application of the system seeks to enhance the visibility of a needle in an image-guided procedure. The enhancement algorithm detects the needle in an ultrasound image and automatically steers the ultrasound beam in the perpendicular direction. This direction produces the strongest echoes and raises the contrast of the needle in subsequent images. The results show improved visibility of a needle in both phantoms and real tissue. The results also demonstrate the flexibility and performance of the system and its suitability for a wide range of research.